Organochlorine Pesticides in the Soils and Atmosphere of Costa Rica

Abstract

A survey of the contamination of the physical environment of Costa Rica with banned organochlorine pesticides (OCPs) relied on sampling air and soil at 23 stations acrossthe country in 2004. Average annual air concentrations, determined with XAD-based passive samplers, and surface soil concentrations were generally low when compared to values reported for North and Central America, which is consistent with relatively low historical domestic use and little atmospheric inflow from neighboring countries. Statistical analysis and concentration maps reveal three types of spatial distribution: alpha-hexachlorocyclohexane and p,p'-DDD had a relatively uniform distribution across the country; other DDT-related species were greatly elevated over the national average at Manuel Antonio, a National Park on the Pacific coast; and dieldrin, lindane, and chlordane-related species had higher concentrations in Costa Rica's populated Central Valley. An altitudinal transect of stations in the Central Valley shows declining air-soil concentration ratios with elevation for lindane, likely driven by atmospheric inversions and soil organic carbon content. Enantiomeric composition of chiral OCPs in air and soil was close to racemic, with slight depletion of (-)-alpha-HCH, (-)-cis-chlordane, and (+)-trans-chlordane. Estimated air-soil fugacity fractions are highly uncertain but indicate equilibrium conditions for most OCPs, net volatilization of lindane at some sites, and net deposition for p,p'-DDE. The study demonstrates an approach for quickly evaluating the spatial distribution of OCPs in an understudied area, identifying regionally important contaminants and areas of elevated concentrations.

Residues of organochlorine pesticides in surface soils from college school yards in Beijing, China

“…In comparison with levels in cotton field (183.07 ± 171.68 ng/g) with heavy pesticide application in Nantong, DDT content in this study was low. In comparison with regions outside China, the levels were close to that in urban soils (110±89 ng/g) from Katowice, Poland (Falandysz et al, 2001) but was much higher than that in mountain soils (5.4 ng/g) from Teide in subtropical Atlantic (Ribes and Grimalt, 2002) and soils not used with DDTs in Costa Rica (Daly et al, 2007). From what is discussed above, the DDT contamination should be a serious problem in Beijing's college school yards.…”

“…They were also detected in the range of 0.03-0.88 ng/g, 0.16-4.84 ng/g, and 0.14-2.41 ng/g for CHLs, HEPTs, and endosulfans, respectively. The average CHLs level (0.51 ± 0.27 ng/g) was much higher than the levels in soils (13.6 pg/g) from Costa Rica (Daly et al, 2007) but comparable with that in soil (0.46 ± 0.53 ng/g) from Krakow, Poland (Falandysz et al, 2001). Technical chlordane is generally used as insecticide, herbicide, and termiticide, and is still being used against termites in China with over 200 tons/year input recently .…”

Current‐use pesticide transport to Costa Rica's high‐altitude tropical cloud forest

“…S1). Each sampling site was divided into a grid, and nine samples were collected with an auger, reaching a depth of 25 cm, which were then mixed with a clean steel shovel and bucket [6,18]. For each site, two subsamples were collected and wrapped in aluminum foil that had been baked at 4508C.…”

“…Whereas monitoring atmospheric levels of pesticides has traditionally relied on active high-volume samplers, more recently passive air samplers (PAS) have found use in mapping the spatial variability of a wide variety of organic pollutants, including CUPs. Daly et al [6,18] All Supplemental Data may be found in the online version of this article. * To whom correspondence may be addressed (frank.wania@utoronto.ca).…”

Effect of pH on DDT degradation in aqueous solution using bimetallic Ni/Fe nanoparticles

“…But its persistence, bioaccumulation, toxicity and long-range atmospheric transport bring many risks to human health and environment. Although it has been regulated under the Stockholm Convention [1], and banned by many countries in the 1970s, DDT and its metabolites are still found at numerous sites in the world [2][3][4].…”